What's the difference between tropical and subtropical storms?

As the tropics begin to heat up in the spring, the National Hurricane Center is on the lookout for weather systems that could develop into potential problems for coastal communities. Sometimes, especially early in the season – or before it even starts – a system becomes a subtropical storm. But what’s the difference between a subtropical storm and a regular tropical storm?

According to the National Hurricane Center, both tropical and subtropical storms have maximum sustained surface wind speeds of 39 miles per hour. Both form from low pressure weather systems over the ocean, but a subtropical storm has the characteristics of both a tropical storm and a non-tropical weather system.

A major difference between the two types of storms is temperature. According to the NHC, both types of storms develop over warm tropical or subtropical waters, a subtropical storm has cooler upper-level temperatures in its core.

Satellite imagery shows the remnants of Subtropical Storm Andrea drifting off the U.S. east coast May 21, 2018(Photo: NOAA)

Another difference is the size of the wind field. While a subtropical storm has a defined center, the maximum sustained winds and thunderstorm activity usually occur relatively far away from it. A tropical storm’s maximum sustained winds are wrapped around the center and will become more tightly wound as the storm intensifies, eventually forming the wall around the distinctive eye feature seen on satellite imagery.

Sheila Dukes hugs her son Ezekiel, 8 as Quan Gloves mops up water from the floor of their rental house in Panama City, FL. Hurricane Michael tore the roof off, flooding the entire wooden structure. Craig Bailey/FLORIDA TODAY

Sheila Dukes hugs her son Ezekiel, 8 as she stands in the ruined kitchen of her rental house in Panama City, FL. Hurricane Michael tore the roof off, flooding the entire wooden structure. Craig Bailey/FLORIDA TODAY

A patient is loaded into a medical helicopter at Gulf Coast Regional Medical Center in Panama City. Patients are being transferred to other hospitals due to the hospital being on generator power. Craig Bailey/FLORIDA TODAY

PANAMA CITY, FL - OCTOBER 11: Kathy Coy stands among what is left of her home after Hurricane Michael destroyed it on October 11, 2018 in Panama City, Florida. She said she was in the home when it was blown apart and is thankful to be alive. The hurricane hit the Florida Panhandle as a category 4 storm. (Photo by Joe Raedle/Getty Images) Joe Raedle, Getty Images

In this aerial view, storm damaged boats are seen in the aftermath of Hurricane Michael on October 11, 2018 in Panama City, Florida. - Residents of the Florida Panhandle woke to scenes of devastation Thursday after Michael tore a path through the coastal region as a powerful hurricane that killed at least two people. (Photo by Brendan Smialowski / AFP) (Photo credit should read BRENDAN SMIALOWSKI/AFP/Getty Images) BRENDAN SMIALOWSKI, AFP/Getty Images

Jim Hankins, pastor of Calvary Baptist Church in Panama City mops up water in his living room Thursday. Hurricane Michael tore off part of their roof, flooring the home. Hankins was once pastor at Parkway Baptist Church in Merritt Island. Craig Bailey/FLORIDA TODAY

In this aerial view, a storm damaged church is seen in the aftermath of Hurricane Michael on October 11, 2018 in Panama City, Florida. - Residents of the Florida Panhandle woke to scenes of devastation Thursday after Michael tore a path through the coastal region as a powerful hurricane that killed at least two people. (Photo by Brendan Smialowski / AFP) (Photo credit should read BRENDAN SMIALOWSKI/AFP/Getty Images) BRENDAN SMIALOWSKI, AFP/Getty Images

The Slaughter family saves their merchandise from their antique store inside the collapsed 15th Street Flea Market in Panama City, Florida after Hurricane Michael on October 11, 2018. - Residents of the Florida Panhandle woke to scenes of devastation Thursday after Michael tore a path through the coastal region as a powerful hurricane that killed at least two people. (Photo by Emily KASK / AFP) (Photo credit should read EMILY KASK/AFP/Getty Images) EMILY KASK, AFP/Getty Images

TOPSHOT - A man walks down the street after Hurricane Michael made landfall on October 10, 2018 in Panama City, Florida. - Michael slammed into the Florida coast on October 10 as the most powerful storm to hit the southern US state in more than a century as officials warned it could wreak "unimaginable devastation." Michael made landfall as a Category 4 storm near Mexico Beach, a town about 20 miles (32kms) southeast of Panama City, around 1:00 pm Eastern time (1700 GMT), the National Hurricane Center said. (Photo by Brendan Smialowski / AFP) (Photo credit should read BRENDAN SMIALOWSKI/AFP/Getty Images) BRENDAN SMIALOWSKI, AFP/Getty Images

MEXICO BEACH, FL - OCTOBER 11: Cars are piled on top of each other after Hurricane Michael passed through the area on October 11, 2018 in Mexico Beach, Florida. The hurricane hit the panhandle area with category 4 winds causing major damage. (Photo by Joe Raedle/Getty Images) Joe Raedle, Getty Images

MEXICO BEACH, FL - OCTOBER 11: Damaged homes are seen after Hurricane Michael passed through the area on October 11, 2018 in Mexico Beach, Florida. The hurricane hit the panhandle area with category 4 winds causing major damage. (Photo by Joe Raedle/Getty Images) Joe Raedle, Getty Images

MEXICO BEACH, FL - OCTOBER 11: Jim Bob looks out on the destruction caused as Hurricane Michael passed through the area on October 11, 2018 in Mexico Beach, Florida. The hurricane hit the panhandle area with category 4 winds causing major damage. (Photo by Joe Raedle/Getty Images) Joe Raedle, Getty Images

The overhang of a gas station is toppled over in the aftermath of Hurricane Michael on October 11, 2018 in Inlet Beach, Florida. - Residents of the Florida Panhandle woke to scenes of devastation Thursday after Michael tore a path through the coastal region as a powerful hurricane that killed at least two people. (Photo by Emily KASK / AFP) (Photo credit should read EMILY KASK/AFP/Getty Images) EMILY KASK, AFP/Getty Images

MEXICO BEACH, FL - OCTOBER 11: Members of the South Florida Search and Rescue team search for survivors in the destruction left after Hurricane Michael passed through the area on October 11, 2018 in Mexico Beach, Florida. The hurricane hit the panhandle area with category 4 winds causing major damage. (Photo by Joe Raedle/Getty Images) Joe Raedle, Getty Images

MEXICO BEACH, FL - OCTOBER 11: Members of the South Florida Search and Rescue team search for survivors in the destruction left after Hurricane Michael passed through the area on October 11, 2018 in Mexico Beach, Florida. The hurricane hit the panhandle area with category 4 winds causing major damage. (Photo by Joe Raedle/Getty Images) Joe Raedle, Getty Images

MEXICO BEACH, FL - OCTOBER 11: Elizabeth Hanson (R) and her daughter, Emaly Hanson hug their neighbor Cindy Clark as they become emotional after dealing with their homes that were heavily damaged when Michael passed through the area on October 11, 2018 in Mexico Beach, Florida. The hurricane hit the panhandle area with category 4 winds causing major damage. (Photo by Joe Raedle/Getty Images) Joe Raedle, Getty Images

In this image made from video and provided by SevereStudios.com, damage from Hurricane Michael is seen in Mexico Beach, Fla. on Thursday, Oct. 11, 2018. Search-and-rescue teams fanned out across the Florida Panhandle to reach trapped people in Michael's wake Thursday as daylight yielded scenes of rows upon rows of houses smashed to pieces by the third-most powerful hurricane on record to hit the continental U.S. (SevereStudios.com via AP) AP

MEXICO BEACH, FL - OCTOBER 11: People walk along a street blocked by a building after Hurricane Michael passed through the area on October 11, 2018 in Mexico Beach, Florida. The hurricane hit the panhandle area with category 4 winds causing major damage. (Photo by Joe Raedle/Getty Images) Joe Raedle, Getty Images

MEXICO BEACH, FL - OCTOBER 11: Elizabeth Hanson (R) and her daughter, become emotional as they look at their home that was heavily damaged when Michael passed through the area on October 11, 2018 in Mexico Beach, Florida. The hurricane hit the panhandle area with category 4 winds causing major damage. (Photo by Joe Raedle/Getty Images) Joe Raedle, Getty Images

MEXICO BEACH, FL - OCTOBER 11: Debris is seen piled in the street after Hurricane Michael passed through the area on October 11, 2018 in Mexico Beach, Florida. The hurricane hit the panhandle area with category 4 winds causing major damage. (Photo by Joe Raedle/Getty Images) Joe Raedle, Getty Images

MEXICO BEACH, FL - OCTOBER 11: A Coast Guard helicopter passes over a damaged home and the foundation of where a home once stood (to the right) before it was blown away by Hurricane Michael as it passed through the area on October 11, 2018 in Mexico Beach, Florida. The hurricane hit the panhandle area with category 4 winds causing major damage. (Photo by Joe Raedle/Getty Images) Joe Raedle, Getty Images

A fallen tree is seen in the aftermath of Hurricane Michael October 11, 2018 in Panama City, Florida. - Residents of the Florida Panhandle woke to scenes of devastation Thursday after Michael tore a path through the coastal region as a powerful hurricane that killed at least two people. (Photo by Brendan Smialowski / AFP) (Photo credit should read BRENDAN SMIALOWSKI/AFP/Getty Images) BRENDAN SMIALOWSKI, AFP/Getty Images

Teresa Sheffield walks out of the remains of her second floor apartment in the aftermath of Hurricane Michael October 11, 2018 in Panama City, Florida. - Residents of the Florida Panhandle woke to scenes of devastation Thursday after Michael tore a path through the coastal region as a powerful hurricane that killed at least two people. (Photo by Brendan Smialowski / AFP) (Photo credit should read BRENDAN SMIALOWSKI/AFP/Getty Images) BRENDAN SMIALOWSKI, AFP/Getty Images

PANAMA CITY BEACH, FL - OCTOBER 11: A roof over a boat storage building is collapsed following Hurricane Michael on October 11, 2018, in Panama City Beach, Florida. Hurricane Michael made landfall Wednesday as a Category 4 hurricane with 155 mph (250 kph) winds and a storm surge of 9 feet (2.7 meters). The hurricane hit the panhandle area with category 4 winds causing major damage. (Photo by Chris O'Meara-Pool/Getty Images) Pool, Getty Images

A man works though the remains of an apartment in the aftermath of Hurricane Michael October 11, 2018 in Panama City, Florida. - Residents of the Florida Panhandle woke to scenes of devastation Thursday after Michael tore a path through the coastal region as a powerful hurricane that killed at least two people. (Photo by Brendan Smialowski / AFP) (Photo credit should read BRENDAN SMIALOWSKI/AFP/Getty Images) BRENDAN SMIALOWSKI, AFP/Getty Images

Storm damage is seen in the aftermath of Hurricane Michael October 11, 2018 in Panama City, Florida. - Residents of the Florida Panhandle woke to scenes of devastation Thursday after Michael tore a path through the coastal region as a powerful hurricane that killed at least two people. (Photo by Brendan Smialowski / AFP) (Photo credit should read BRENDAN SMIALOWSKI/AFP/Getty Images) BRENDAN SMIALOWSKI, AFP/Getty Images

Traffic is denied access to Interstate 10 West at exit 147 in Gadsden County, Fla. Oct. 11, 2018. Downed trees and power lines from Hurricane Michael are preventing non-essential travel to Panama City using 10 West. Portions of 10 West are closed for 80 miles. KINFAY MOROTI, USA TODAY NETWORK

Panama City resident Albert Singleton picks his way down a derby-strewn sidewalk his way back to the house that he and his cousin shared in Panama City. Hurricane Michael tore off the roof and front porch.
Oct. 11, 2018; Denver, CO USA; xxx Mandatory credit: Trevor Hughes-USA TODAY NETWORK Trevor Hughes, Trevor Hughes-USA TODAY NETWORK

In St. Marks, Fla. on Thursday, Oct. 11, 2018 St. Marks Seafood employees work to remove the river sludge that blankets the ground after Hurricane Michael tears through the panhandle. Alicia Devine/Democrat, Alicia Devine/Democrat

In St. Marks, Fla. on Thursday, Oct. 11, 2018 St. Marks Seafood employees work to remove the river sludge that blankets the ground after Hurricane Michael tears through the panhandle. Alicia Devine/Democrat, Alicia Devine/Democrat

In this image made from video and provided by SevereStudios.com, damage from Hurricane Michael is seen in Mexico Beach, Fla. on Thursday, Oct. 11, 2018. Search-and-rescue teams fanned out across the Florida Panhandle to reach trapped people in Michael's wake Thursday as daylight yielded scenes of rows upon rows of houses smashed to pieces by the third-most powerful hurricane on record to hit the continental U.S. (SevereStudios.com via AP) AP

In this image made from video and provided by SevereStudios.com, damage from Hurricane Michael is seen in Mexico Beach, Fla. on Thursday, Oct. 11, 2018. Search-and-rescue teams fanned out across the Florida Panhandle to reach trapped people in Michael's wake Thursday as daylight yielded scenes of rows upon rows of houses smashed to pieces by the third-most powerful hurricane on record to hit the continental U.S. (SevereStudios.com via AP) AP

In this image made from video and provided by SevereStudios.com, damage from Hurricane Michael is seen in Mexico Beach, Fla. on Thursday, Oct. 11, 2018. Search-and-rescue teams fanned out across the Florida Panhandle to reach trapped people in Michael's wake Thursday as daylight yielded scenes of rows upon rows of houses smashed to pieces by the third-most powerful hurricane on record to hit the continental U.S. (SevereStudios.com via AP) AP

In this image made from video and provided by SevereStudios.com, damage from Hurricane Michael is seen in Mexico Beach, Fla. on Thursday, Oct. 11, 2018. Search-and-rescue teams fanned out across the Florida Panhandle to reach trapped people in Michael's wake Thursday as daylight yielded scenes of rows upon rows of houses smashed to pieces by the third-most powerful hurricane on record to hit the continental U.S. (SevereStudios.com via AP) AP

Haley Nelson inspects damages to her family properties in the Panama City, Fla., spring field area after Hurricane Michael made landfall in Florida's Panhandle on Wednesday, Oct. 10, 2018. Supercharged by abnormally warm waters in the Gulf of Mexico, Hurricane Michael slammed into the Florida Panhandle with terrifying winds of 155 mph Wednesday, splintering homes and submerging neighborhoods before continuing its march inland. (Pedro Portal/Miami Herald via AP) Pedro Portal, AP

In this image made from video and provided by SevereStudios.com, damage from Hurricane Michael is seen in Mexico Beach, Fla. on Thursday, Oct. 11, 2018. Search-and-rescue teams fanned out across the Florida Panhandle to reach trapped people in Michael's wake Thursday as daylight yielded scenes of rows upon rows of houses smashed to pieces by the third-most powerful hurricane on record to hit the continental U.S. (SevereStudios.com via AP) AP

Forecasters warn that, for people on the ground, there is little difference between a tropical and subtropical storm. Both bring high winds, dangerous surf and potential flooding.

"The wind speeds of tropical and subtropical systems are the same, so we are telling folks not to focus on the wording because the impacts will be the same,” said Morgan Barry, a meteorologist with the National Weather Service, ahead of Subtropical Storm Alberto in 2018.